Coating materials of the kind that are spread over a base surface have long been used in an effort to satisfy decorative and protective goals. Paint, originally a decorative coloring material, can afford protection from weathering. Development to improve adhesion, durability and easier application, along with improved protection, lead to the use of polymeric materials in paints.
The decoration of cement products and surfaces and their protection led to the development of flexible mortars. These mortars, which flex only imperceptably but far more than concrete, are essentially Portland cement mortars to which polymers are added. The three main ingredients of cement, tricalcium silicate, and dicalcium silicate, and tricalcium aluminate, hydrolize at different rates. The addition of polymers modifies the hardening process in a way that is not well understood. Different polymer additives modify properties in the hardening process and in the end result which suggests differences not only in degree but in the process itself. As a consequence, improvements are discovered rather than engineered. A number of cement-plastic combinations have been discovered to provide acceptable results as protective back plasters and decorative concrete overcoatings, even as protective overcoatings for roofs.
What has not been found is a paint or mortar which is a suitable repair material for concrete. Paints and mortars have not been made in a form that permits their use as a structural, load bearing element. It has not been possible to repair a sidewalk or a road by applying a layer of paint or of mortar to the sidewalk or road surface. Integrity of a cementitious overcoating is not assured in previously known materials until the thickness is so great as to constitute a new sidewalk or road. No cementitious compound or system has been known which can compete with asphalt as a repair material for concrete sidewalks, driveways, parking lots and roads. This invention provides such a material and "systems" of materials.